1. Field
Example embodiments relate to a frame conversion apparatus and method and a frame type detection apparatus and method.
2. Description of the Related Art
A movie image may be displayed at a first number of frames per second, for example, 24 frames per second and a television (TV) image may be displayed at a second number of frames per second, for example, 30 frames per second. In order to broadcast a movie image in the form of a TV image, the frame rate of the movie image must be adjusted to conform with that of the TV image. Thus, a process known as “telecine” is used. Telecine is a process of making a new frame by duplicating some fields in order to convert an image of 24 frames per second into an image of 30 frames per second. For example, a movie image may include four frames for every ⅙ of a second, and a TV image may include five frames for every ⅙ of a second. Thus, in order to broadcast the movie image in the form of a TV image, a process of converting four frames into five frames, which is referred to as telecine, may be performed.
In telecine, new frames may be created from combinations of existing frames and used as converted frames. Also, some frames may be used directly as converted frames. New frames obtained from combinations of existing frames may be referred to as telecine frames, and frames used directly without being changed may be referred to as progressive frames.
Inverse telecine is a process in which telecine is performed in reverse. In order to perform inverse telecine, it must be determined whether frames on which inverse telecine is to be performed are telecine frames or progressive frames.
A TV broadcast station may compress frames, which are output through telecine, according to an MPEG-2 standard. Compression of the frames may include a Discrete Cosine Transform (hereinafter referred to as “DCT”) operation. A DCT operation may be categorized into a field DCT operation and a frame DCT operation. A field DCT operation may be used on telecine frames and a frame DCT operation may be used on progressive frames. Thus, in order to decompress data compressed according to the MPEG-2 standard, the type of DCT operation used to compress the data must be determined. In order to determine the type of DCT operation used to compress the data, it must be determined whether the data frames are telecine frames or progressive frames.
Whether a target frame is a telecine frame or a progressive frame may be determined by computing a motion vector between the target frame and neighboring frames or performing a frequency analysis of the target frame. Therefore, in addition to a decompressing operation, additional operations must be further performed to compute a motion vector or perform the frequency analysis. Thus, calculators having a complicated structure are needed. Also, it may be difficult to determine whether frames are telecine frames in real time.